<template>
  <view>
    <!-- 自定义组件 -->
    <my-search @click="gotoSearch()" ></my-search>

	<view class="scroll-view-container">
    <!-- 左侧的滚动视图区域 -->
		<scroll-view scroll-y="true" class="left-scroll-view" :style="{height:wh+'px'}">
      <block v-for="(item,i) in cateList" :key="i">
        <view class="['left-scroll-view-item',i===active ? 'active':'']" @click="activeChange(i)">{{item.cat_name}}</view>
      </block>
		</scroll-view>
    
    <!-- 右侧的滚动视图区域 -->
		<scroll-view scroll-y="true" class="right-scroll-view" :style="{height:wh+'px'}" :scroll-top="scrollTop" >
		 <view class="cate-lv2" v-for="(item2, i2) in cateLevel2" :key="i2">
		     <view class="cate-lv2-title">/ {{item2.cat_name}} /</view>
		     <!-- 动态渲染三级分类的列表数据 -->
		     <view class="cate-lv3-list">
		       <!-- 三级分类 Item 项 -->
		       <view class="cate-lv3-item" v-for="(item3, i3) in item2.children" :key="i3" @click="gotoGoodList(item3)">
		         <!-- 图片 -->
		         <image :src="item3.cat_icon"></image>
		         <!-- 文本 -->
		         <text>{{item3.cat_name}}</text>
		       </view>
		     </view>
		   </view>
		</scroll-view>
	</view>
  </view>
</template>

<script>
	export default {
		data() {
			return {
        // 窗口可用高度 = 屏幕高度 - navigatBar高度 - tabBar高度
				wh:0,
        cateList:[],
        cateLevel2: [],
        active:0,
        scrollTop:0
			};
		},
    onLoad() {
      // 获取当前系统信息
      const sysInfo=uni.getSystemInfoSync()
      // 为wh窗口可用高度动态赋值
      this.wh = sysInfo.windowHeight-50
      this.getCateList()
    },
    methods:{
    async  getCateList(){
        const {data:res} = await uni.$http.get('/categories')
        if(res.meta.status !== 200 ) return uni.$showMsg()
        this.cateList=res.message
        this.cateLevel2=res.message[0].children
      },
      activeChange(i){
        this.active = i
        this.cateLevel2=this.cateList[i].children
        this.scrollTop=this.scrollTop === 0 ? 1: 0
      },
      gotoGoodList(item3){
        uni.navigateTo({
          url:'/subpkg/goods_list/goods_list?cid='+item3.cat_id
        })
      },
      gotoSearch(){
        uni.navigateTo({
          url:'/subpkg/search/search'
        })
      }
    }
	}
</script>

<style lang="scss">
.scroll-view-container {
  display: flex;

  .left-scroll-view {
    width: 120px;

    .left-scroll-view-item {
      line-height: 60px;
      background-color: #f7f7f7;
      text-align: center;
      font-size: 12px;
      }
}

.cate-lv2-title {
  font-size: 12px;
  font-weight: bold;
  text-align: center;
  padding: 15px 0;
  }
  .cate-lv3-list {
    display: flex;
    flex-wrap: wrap;
  
    .cate-lv3-item {
      width: 33.33%;
      margin-bottom: 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
  
      image {
        width: 60px;
        height: 60px;
      }
  
      text {
        font-size: 12px;
      }
    }
  }



      // 激活项的样式
      &.active {
        background-color: #ffffff;
        position: relative;

        // 渲染激活项左侧的红色指示边线
        &::before {
          content: ' ';
          display: block;
          width: 3px;
          height: 30px;
          background-color: #c00000;
          position: absolute;
          left: 0;
          top: 50%;
          transform: translateY(-50%);
        }
      }
    
  
}
</style>
